LKB1/STRADは,神経の偏極化中に軸索のイニシアチブを促進します
Maya Shelly1, Laura Cancedda, Sarah Heilshorn
1Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA.
Cell
|May 8, 2007
まとめ
LKB1およびSTRADタンパク質の局所的蓄積は,発達中のニューロンにおける軸索の開始を信号する. このプロセスは,適切な軸索分化のために,LKB1のタンパク質キナーゼA (PKA) 依存型リン酸化を必要とします.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- 発達生物学 発達生物学について
背景:
- アクソンとデンドライトの分化は,神経細胞の発達における基本的なプロセスです.
- ニューロンの極性の確立は,神経系の適切な機能に不可欠です.
- LKB1とSTRADが神経の極性や軸索形成に果たす役割は十分に理解されていません.
研究 の 目的:
- 発達中のニューロンにおけるアクソン分化におけるLKB1およびSTRADタンパク質の役割を調査する.
- LKB1とSTRADが軸索形成を調節する分子メカニズムを決定する.
- 早期アクソン発起に関与するシグナル伝達経路を特定する.
主な方法:
- 培養された海馬の神経細胞と発達中の皮質の神経細胞を in vivo で利用した.
- LKB1とSTRADのsiRNA媒介のノックダウンと過剰発現が使用されています.
- サイト指向型変異性 (LKB1 ((S431A)) を使用して,LKB1のセルリン431 (S431) でのリン酸化の効果を調査しました.
- PKA活性化剤 (BDNF,dibutyryl-cAMP) が軸索の分化に与える影響を評価した.
主要な成果:
- LKB1とSTRADの蓄積は,その後の軸索の分化と相関する無差別なニューライトに存在します.
- LKB1またはSTRADのダウンレギュレーションは軸索形成を阻害し,過剰発現は複数の軸索を引き起こした.
- LKB1とのSTRADの相互作用はS431でLKB1のリン酸化を促進し,LKB1レベルを上昇させた.
- 非リン酸化可能なLKB1変異体 (LKB1(S431A)) の過剰発現は,試験管内および体内での軸索分化を阻害しました.
- PKAに依存するLKB1のリン酸化は,BDNFまたはディブチリル-cAMP誘発のアクソン分化に不可欠でした.
結論:
- LKB1とSTRADの局所的な蓄積は,軸索の開始のための初期の信号として機能します.
- S431におけるLKB1のPKA依存型リン酸化は,軸索の微分化における重要なステップである.
- これらの発見は,神経の極性および軸索形成を調節する重要な分子機構を明らかにしています.
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